A second-order doubles correction to excitation energies in the random-phase approximation

O Christiansen; KL Bak; Henrik Koch; SPA Sauer

A second-order doubles correction to excitation energies in the random-phase approximation

O Christiansen^*, KL Bak, Henrik Koch, SPA Sauer

^*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review

Abstract

A computationally tractable doubles correction to excitation energies obtained in the random-phase approximation (RPA(D)) is presented. It gives excitation energies correct through second order in the ground-state fluctuation potential. RPA(D) has been tested for H2O, N-2, Ne, CH2, BH and C-2 using full configuration interaction (FCI) results as benchmarks. Comparison is made with other existing models of similar complexity. Overall the accuracy of excitation energies calculated using RPA(D) is similar to that obtained in the CC2, CIS(D) and SOPPA methods. The errors of the random-phase approximation excitation energies are typically reduced by a factor of two using the RPA(D) correction. The mean absolute deviation of RPA(D) and FCI excitation energies is 0.51 eV and for the majority of the excitations the RPA(D) results are lower than the FCI results. (C) 1998 Published by Elsevier Science B.V.

Originalsprog	Engelsk
Tidsskrift	Chemical Physics Letters
Vol/bind	284
Nummer	1-2
Sider (fra-til)	47-55
Antal sider	9
ISSN	0009-2614
Status	Udgivet - 20 feb. 1998

Citationsformater

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title = "A second-order doubles correction to excitation energies in the random-phase approximation",

abstract = "A computationally tractable doubles correction to excitation energies obtained in the random-phase approximation (RPA(D)) is presented. It gives excitation energies correct through second order in the ground-state fluctuation potential. RPA(D) has been tested for H2O, N-2, Ne, CH2, BH and C-2 using full configuration interaction (FCI) results as benchmarks. Comparison is made with other existing models of similar complexity. Overall the accuracy of excitation energies calculated using RPA(D) is similar to that obtained in the CC2, CIS(D) and SOPPA methods. The errors of the random-phase approximation excitation energies are typically reduced by a factor of two using the RPA(D) correction. The mean absolute deviation of RPA(D) and FCI excitation energies is 0.51 eV and for the majority of the excitations the RPA(D) results are lower than the FCI results. (C) 1998 Published by Elsevier Science B.V.",

keywords = "COUPLED-CLUSTER SINGLES, FULL CONFIGURATION-INTERACTION, MOLECULAR CALCULATIONS, EXCITED-STATES, MODEL, POLARIZABILITIES, NEON, CCSD, CC2",

author = "O Christiansen and KL Bak and Henrik Koch and SPA Sauer",

year = "1998",

month = feb,

day = "20",

language = "English",

volume = "284",

pages = "47--55",

journal = "Chemical Physics Letters",

issn = "0009-2614",

publisher = "Elsevier BV",

number = "1-2",

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TY - JOUR

T1 - A second-order doubles correction to excitation energies in the random-phase approximation

AU - Christiansen, O

AU - Bak, KL

AU - Koch, Henrik

AU - Sauer, SPA

PY - 1998/2/20

Y1 - 1998/2/20

N2 - A computationally tractable doubles correction to excitation energies obtained in the random-phase approximation (RPA(D)) is presented. It gives excitation energies correct through second order in the ground-state fluctuation potential. RPA(D) has been tested for H2O, N-2, Ne, CH2, BH and C-2 using full configuration interaction (FCI) results as benchmarks. Comparison is made with other existing models of similar complexity. Overall the accuracy of excitation energies calculated using RPA(D) is similar to that obtained in the CC2, CIS(D) and SOPPA methods. The errors of the random-phase approximation excitation energies are typically reduced by a factor of two using the RPA(D) correction. The mean absolute deviation of RPA(D) and FCI excitation energies is 0.51 eV and for the majority of the excitations the RPA(D) results are lower than the FCI results. (C) 1998 Published by Elsevier Science B.V.

AB - A computationally tractable doubles correction to excitation energies obtained in the random-phase approximation (RPA(D)) is presented. It gives excitation energies correct through second order in the ground-state fluctuation potential. RPA(D) has been tested for H2O, N-2, Ne, CH2, BH and C-2 using full configuration interaction (FCI) results as benchmarks. Comparison is made with other existing models of similar complexity. Overall the accuracy of excitation energies calculated using RPA(D) is similar to that obtained in the CC2, CIS(D) and SOPPA methods. The errors of the random-phase approximation excitation energies are typically reduced by a factor of two using the RPA(D) correction. The mean absolute deviation of RPA(D) and FCI excitation energies is 0.51 eV and for the majority of the excitations the RPA(D) results are lower than the FCI results. (C) 1998 Published by Elsevier Science B.V.

KW - COUPLED-CLUSTER SINGLES

KW - FULL CONFIGURATION-INTERACTION

KW - MOLECULAR CALCULATIONS

KW - EXCITED-STATES

KW - MODEL

KW - POLARIZABILITIES

KW - NEON

KW - CCSD

KW - CC2

M3 - Journal article

SN - 0009-2614

VL - 284

SP - 47

EP - 55

JO - Chemical Physics Letters

JF - Chemical Physics Letters

IS - 1-2

ER -

A second-order doubles correction to excitation energies in the random-phase approximation

Abstract

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Citationsformater